This repository contains .csv files with phenological data of Horse Chestnut (Aesculus Hippocastanum) Trees in Amsterdam, on a gradient from the city centre to surrounding rural areas. Every year, students will monitor the onset of buds on these trees and gather climatic data of the past winter season to study trends in urban phenology. This repository contains a field form to be used for monitoring the trees, a dataset into which students will merge their data and a final dataset that will be compiled by the course staff based on the students' entries.